Integral core bumpers

ABSTRACT

A casting core assembly is disclosed herein. The casting core assembly comprises a casting core and a bumper assembly. The bumper assembly is disposed on an outer surface of the casting core. The bumper assembly comprises a receptacle and a metal apparatus. The metal apparatus may be a pin, a sphere, or the like.

FIELD

The present disclosure relates to airfoils for gas turbine engines, andin particular, to ceramic cores having integral bumpers.

BACKGROUND

In gas turbine engines, airfoils, such as rotor blades and stator vanesmay include internal cavities in which cooling air is introduced toconvectively cool the airfoil. Internal cavities may be formed by aceramic core during the manufacturing process for airfoils. Bumpers canbe added to ceramic cores to keep the ceramic core centered in a castingduring manufacturing.

SUMMARY

A casting core assembly is disclosed herein. The casting core assemblymay comprise: a casting core having an outer surface; a bumper disposedon the outer surface, the bumper comprising a receptacle; and a metalapparatus partially disposed in the receptacle of the bumper, a portionof the metal apparatus extending outward from the bumper.

In various embodiments, the metal apparatus is a pin. The pin maycomprise a proximal end and a distal end disposed opposite the proximalend, and wherein the proximal end is disposed at a depth below the outersurface of the casting core. The metal apparatus may be a sphere. Thebumper may be integral to the casting core. The metal apparatus may becoupled to the bumper by at least one of an adhesive or a mechanicallock. The metal apparatus may be configured to merge into an airfoilcasting.

A method of manufacturing a casting assembly is disclosed herein. Themethod may comprise: forming a casting core having an outer surface;inserting a pin into the outer surface of the casting core; injectingceramic composite around the pin; and heating the casting core, theinjected ceramic composite and the pin.

In various embodiments, heating the casting core may further compriseforming a casting core assembly including a bumper assembly. The methodmay further comprise: injecting a wax around the casting core and thebumper assembly. The wax may enclose the bumper assembly. The method mayfurther comprise forming an external shell around the wax. The formingthe external shell may further comprise dipping the wax into a ceramicmatrix slurry. The method may further comprise heating the castingassembly and removing the wax from the casting assembly.

A method of manufacturing a casting assembly is disclosed herein. Themethod may comprise: forming a casting core having a bumper disposed onan outer surface of the casting core, the bumper comprising areceptacle; inserting a metal apparatus into the receptacle of thebumper; and coupling the metal apparatus to the bumper.

In various embodiments, the coupling the metal apparatus is via at leastone of a mechanical lock and an adhesive. The method may furthercomprise injecting wax around the casting core, the bumper, and themetal apparatus. The method may further comprise forming an externalshell around the injected wax. The method may further comprise heatingthe casting assembly. The metal apparatus may be selected from a groupconsisting of a pin and a sphere.

The foregoing features and elements may be combined in variouscombinations without exclusivity, unless expressly indicated otherwise.These features and elements as well as the operation thereof will becomemore apparent in light of the following description and the accompanyingdrawings. It should be understood, however, the following descriptionand drawings are intended to be exemplary in nature and non-limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter of the present disclosure is particularly pointed outand distinctly claimed in the concluding portion of the specification. Amore complete understanding of the present disclosure, however, may bestbe obtained by referring to the detailed description and claims whenconsidered in connection with the figures, wherein like numerals denotelike elements.

FIG. 1 illustrates an exemplary gas turbine engine, in accordance withvarious embodiments;

FIG. 2 illustrates an exemplary air foil having an internal coolingpassage, in accordance with various embodiments;

FIG. 3 illustrates a cast core for casting an airfoil, in accordancewith various embodiments;

FIG. 4 illustrates a cast core including a bumper assembly, inaccordance with various embodiments;

FIG. 5A illustrates a cross-sectional view of a casting assembly priorto casting, in accordance with various embodiments;

FIG. 5B illustrates a cross-sectional view of a casting assembly afterwax removal and prior to casting, in accordance with variousembodiments;

FIG. 6 illustrates a cast core including a bumper assembly, inaccordance with various embodiments;

FIG. 7A illustrates a cross-sectional view of a casting assembly priorto casting, in accordance with various embodiments;

FIG. 7B illustrates a cross-sectional view of a casting assembly afterwax removal and prior to casting, in accordance with variousembodiments;

FIG. 8 illustrates a method of manufacturing a cast core assembly, inaccordance with various embodiments; and

FIG. 9 illustrates a method of manufacturing a cast core assembly, inaccordance with various embodiments.

DETAILED DESCRIPTION

All ranges and ratio limits disclosed herein may be combined. It is tobe understood that unless specifically stated otherwise, references to“a,” “an,” and/or “the” may include one or more than one and thatreference to an item in the singular may also include the item in theplural.

The detailed description of various embodiments herein makes referenceto the accompanying drawings, which show various embodiments by way ofillustration. While these various embodiments are described insufficient detail to enable those skilled in the art to practice thedisclosure, it should be understood that other embodiments may berealized and that logical, chemical, and mechanical changes may be madewithout departing from the spirit and scope of the disclosure. Thus, thedetailed description herein is presented for purposes of illustrationonly and not of limitation. For example, the steps recited in any of themethod or process descriptions may be executed in any order and are notnecessarily limited to the order presented. Furthermore, any referenceto singular includes plural embodiments, and any reference to more thanone component or step may include a singular embodiment or step. Also,any reference to attached, fixed, connected, or the like may includepermanent, removable, temporary, partial, full, and/or any otherpossible attachment option. Any reference related to fluidic coupling toserve as a conduit for cooling airflow and the like may includepermanent, removable, temporary, partial, full, and/or any otherpossible attachment option. Additionally, any reference to withoutcontact (or similar phrases) may also include reduced contact or minimalcontact. Cross hatching lines may be used throughout the figures todenote different parts but not necessarily to denote the same ordifferent materials.

As used herein, “aft” refers to the direction associated with theexhaust (e.g., the back end) of a gas turbine engine. As used herein,“forward” refers to the direction associated with the intake (e.g., thefront end) of a gas turbine engine.

A first component that is “radially outward” of a second component meansthat the first component is positioned at a greater distance away fromthe engine central longitudinal axis than the second component. A firstcomponent that is “radially inward” of a second component means that thefirst component is positioned closer to the engine central longitudinalaxis than the second component. In the case of components that rotatecircumferentially about the engine central longitudinal axis, a firstcomponent that is radially inward of a second component rotates througha circumferentially shorter path than the second component. Theterminology “radially outward” and “radially inward” may also be usedrelative to references other than the engine central longitudinal axis.A first component that is “radially outward” of a second component meansthat the first component is positioned at a greater distance away fromthe engine central longitudinal axis than the second component. As usedherein, “distal” refers to the direction outward, or generally, awayfrom a reference component. As used herein, “proximal” refers to adirection inward, or generally, towards the reference component.

The next generation turbofan engines are designed for higher efficiencyand use higher pressure ratios and higher temperatures in the highpressure compressor than are conventionally experienced. These higheroperating temperatures and pressure ratios create operating environmentsthat cause thermal loads that are higher than the thermal loadsconventionally experienced, which may shorten the operational life ofcurrent components.

The present disclosure relates to casting core assemblies. Casting coreassemblies may comprise a casting core and a bumper assembly. The bumperassembly may comprise a bumper and a metal apparatus. The bumper extendsfrom an outer surface of the casting core and may be integral to thecasting core. The bumper may comprise a receptacle. The metal apparatusmay be disposed within the receptacle of the bumper. The metal apparatusmay be coupled to the bumper while the casting core is being formed orthe casting core assembly may be formed and the metal apparatus may becoupled to the receptacle via an adhesive or a mechanical lock. Thecasting core assembly may eliminate the hand work of inserting a metalapparatus into wax patterns and blending them off post cast. The bumperassembly may allow repeatable positioning of an airfoil because it's acomponent of the casting core assembly. The bumper assembly mayeliminate holes produced through an airfoil and/or between ribs duringcasting.

Referring now to FIG. 1 , an exemplary gas turbine engine 20 is shown,in accordance with various embodiments. Gas turbine engine 20 may be atwo-spool turbofan that generally incorporates a fan section 22, acompressor section 24, a combustor section 26 and a turbine section 28.In operation, fan section 22 can drive coolant (e.g., air) along abypass-flow path B while compressor section 24 can drive coolant along acore-flow path C for compression and communication into combustorsection 26 then expansion through turbine section 28. Although depictedas a turbofan gas turbine engine 20 herein, it should be understood thatthe concepts described herein are not limited to use with turbofans asthe teachings may be applied to other types of turbine engines includingthree-spool architectures.

Gas turbine engine 20 may generally comprise a low speed spool 30 and ahigh speed spool 32 mounted for rotation about an engine centrallongitudinal axis A-A′ relative to an engine static structure 36 viaseveral bearing systems 38, 38-1, and 38-2. It should be understood thatvarious bearing systems 38 at various locations may alternatively oradditionally be provided, including for example, bearing system 38,bearing system 38-1, and bearing system 38-2.

Low speed spool 30 may generally comprise an inner shaft 40 thatinterconnects a fan 42, a low-pressure compressor 44 and a low-pressureturbine 46. Inner shaft 40 may be connected to fan 42 through a gearedarchitecture 48 that can drive fan 42 at a lower speed than low speedspool 30. Geared architecture 48 may comprise a gear assembly 60enclosed within a gear housing 62. Gear assembly 60 couples inner shaft40 to a rotating fan structure. High speed spool 32 may comprise anouter shaft 50 that interconnects a high-pressure compressor 52 andhigh-pressure turbine 54. Airfoils 55 coupled to a rotor ofhigh-pressure turbine may rotate about the engine central longitudinalaxis A-A′ or airfoils 55 coupled to a stator may be rotationally fixedabout engine central longitudinal axis A-A′.

A combustor 56 may be located between high-pressure compressor 52 andhigh-pressure turbine 54. Mid-turbine frame 57 may support one or morebearing systems 38 in turbine section 28. Inner shaft 40 and outer shaft50 may be concentric and rotate via bearing systems 38 about the enginecentral longitudinal axis A-A′, which is collinear with theirlongitudinal axes. As used herein, a “high-pressure” compressor orturbine experiences a higher pressure than a corresponding“low-pressure” compressor or turbine.

The core airflow along core-flow path C may be compressed bylow-pressure compressor 44 then high-pressure compressor 52, mixed andburned with fuel in combustor 56, then expanded over high-pressureturbine 54 and low-pressure turbine 46. Mid-turbine frame 57 includesairfoils 59, which are in the core airflow path. Turbines 46, 54rotationally drive the respective low speed spool 30 and high speedspool 32 in response to the expansion.

Gas turbine engine 20 may be, for example, a high-bypass ratio gearedaircraft engine. In various embodiments, the bypass ratio of gas turbineengine 20 may be greater than about six (6). In various embodiments, thebypass ratio of gas turbine engine 20 may be greater than ten (10). Invarious embodiments, geared architecture 48 may be an epicyclic geartrain, such as a star gear system (sun gear in meshing engagement with aplurality of star gears supported by a carrier and in meshing engagementwith a ring gear) or other gear system. Geared architecture 48 may havea gear reduction ratio of greater than about 2.3 and low-pressureturbine 46 may have a pressure ratio that is greater than about five(5). In various embodiments, the bypass ratio of gas turbine engine 20is greater than about ten (10:1). In various embodiments, the diameterof fan 42 may be significantly larger than that of the low-pressurecompressor 44. Low-pressure turbine 46 pressure ratio may be measuredprior to inlet of low-pressure turbine 46 as related to the pressure atthe outlet of low-pressure turbine 46 prior to an exhaust nozzle. Itshould be understood, however, that the above parameters are exemplaryof various embodiments of a suitable geared architecture engine and thatthe present disclosure contemplates other turbine engines includingdirect drive turbofans.

Airfoil 55 may be an internally cooled component of gas turbine engine20. Trip strips may be located in internal cooling cavities ofinternally cooled engine parts. Internally cooled engine parts may bediscussed in the present disclosure in terms of airfoils. However, thepresent disclosure applies to any internally cooled engine component(e.g., blade outer air seals, airfoil platforms, combustor liners,blades, vanes, or any other internally cooled component in a gas turbineengine).

With reference to FIG. 2 , an airfoil 100 is shown with cooling passage108, in accordance with various embodiments. Although an airfoil isshown, the present disclosure applies to any internally cooled part(e.g., blade outer air seals, airfoil platforms, combustor components,etc.). Airfoil 100 has a pressure side 102, a leading edge 104, and atrailing edge 106. Airfoil 100 also includes top 111 and suction side113. Pressure side 102 surface is partially cutaway to illustratecooling passages 108 defined be internal walls of airfoil 100. Hot airflowing through a gas turbine engine may first contact leading edge 104,flow along pressure side 109 and/or suction side 113 and leave airfoilat trailing edge 106.

In various embodiments, material 107 may define internal passages suchas cooling passage 108. Cooling passage 108 is oriented generally in adirection from platform 112 and attachment 114 towards top 111 (i.e., aradial direction when airfoil 100 is installed in a turbine). Airfoil100 may contain multiple cooling passages or chambers similar to coolingpassage 108 oriented in various directions with varying hydraulicdiameters. The internal cooling passages may be interconnected. Multiplecooling features may appear in the internal cooling passages, asillustrated in further detail below.

With reference to FIG. 3 , a cast core 200, in accordance with variousembodiments, is illustrated. Cast core 200 may be used in castingairfoil 100 to define internal features. Cast core 200 may definefeatures aft of leading edge 104 and up to trailing edge 106 in airfoil100. Cast core 200 may extend beyond trailing edge 106 of airfoil 100during the casting process to define aft cooling openings. Cast core 200may define cooling passage 108 of airfoil 100 and cooling featurestherein. In that regard, both airfoil 100 and cast core 200 may have thecooling passages and cooling features described herein.

The features of cast core 200 may be negatives of the cooling featuresdescribed below with respect to an airfoil 100. Stated another way,cavities, openings, passages, and the like of airfoil 100 may be definedby material in cast core 200. Cooling features and pedestals of airfoil100 that are defined by material in airfoil 100 as described herein maybe formed as passages and openings in cast core 200. Thus, the featuresdescribed below as bumpers and cooling passages may describe thestructure of an airfoil 100 and/or a cast core 200.

Cast core 200 may be placed in a mold, and the material to form acomponent (e.g., airfoil 100) may be deposited in the mold. Cast core200 may be removed from the component, leaving cavities and the desiredcooling features in the component. Airfoil 100 (as well as othercomponents using fluid turbulation) may be made from an austeniticnickel-chromium-based alloy such as that sold under the trademarkInconel® which is available from Special Metals Corporation of NewHartford, N.Y., USA, or other materials capable of withstanding exhausttemperatures.

With reference to FIG. 4 , a cast core 200 including a bumper assembly300, in accordance with various embodiments, is illustrated. Cast core200 comprises an outer surface 202 and a bumper assembly 300 extendingoutward from outer surface 202. In various embodiments, bumper assembly300 is integral to the cast core 200. Bumper assembly 300 comprises abumper 310 and a pin 320. The pin 320 may be disposed partially withinthe bumper 310.

In various embodiments, the bumper 310 comprises a fillet 312 coupling aproximal edge 313 of bumper 310 to the outer surface 202 of the castcore 200. The fillet 312 may reduce stress concentrations during thecasting process. In various embodiments, bumper 310 is a truncated cone314 extending from proximal edge 313 to distal edge 315. The bumper 310further comprises a receptacle 316 extending from distal edge 315 intothe cast core 200. Receptacle 316 may be a recess and may comprise acylindrical shape. In various embodiments, the receptacle 316 may have adepth past outer surface 202 of the cast core 200. In variousembodiments, the bumper 310 is integral to the cast core 200. The bumpermay be made from ceramic composite, or any other material known in theart. Similarly, the cast core may be made from ceramic composite, or anyother material known in the art.

The pin 320 may comprise a proximal end 322 and a distal end 324. Invarious embodiments, proximal end 322 is disposed within, and surroundedby, receptacle 316 of bumper 310. In various embodiments, distal end 324of pin 320 may be at a first height measured perpendicular to outersurface 202 of the cast core 200 that is greater than a second height ofthe bumper 310. In various embodiments, pin 320 is made from any metalalloy known in the art, such as platinum, or the like. In variousembodiments, pin 320 is cylindrical in shape.

In various embodiments, pin 320 may be coupled to bumper 310 byinserting the pin 320 into cast core 200 to a depth below outer surface202. Next, bumper 310 may be injected partially around the pin 320 toform receptacle 316 and capture the pin 320 within bumper 310. Thebumper 310 may then be hardened with the cast core 200 to couple the pin320 and the bumper 310 to the cast core 200. In various embodiments,bumper 310 may be integral to cast core 200. The bumper 310 may comprisethe receptacle 316. The pin 320 may be inserted into the receptacle 316and coupled via an adhesive or a mechanical lock. By integrating the pin320 into the cast core 200, the manual process of inserting a pin into awax pattern and blending the pin 320 off post casting may be eliminated.

With reference to FIG. 5A, a cross-sectional view of a casting assembly400 prior to casting, in accordance with various embodiments, isillustrated. In various embodiments, the casting assembly 400 comprisesan external shell 410, a core assembly 420, and wax 430 disposed betweenthe core assembly 420 and the external shell 410. In variousembodiments, external shell 410 comprises an outer surface 412 and aninner surface 414 disposed opposite the outer surface. In variousembodiments, casting assembly 400 comprises a cast core 200 and a bumperassembly 300. In various embodiments, distal end 324 of pin 320 isdisposed between 0.000 inches and 0.006 inches (0.000 cm and 0.015 cm)from inner surface 414 of external shell 410, or between 0.002 inchesand 0.006 inches (0.005 cm and 0.015 cm), or between 0.003 inches and0.005 inches (0.008 cm and 0.013 cm). In various embodiments, distal end324 of pin 320 contacts inner surface 414 of external shell 410.

In various embodiments, the external shell 410 is made of ceramiccomposite, or any other material known in the art. In variousembodiments, the core assembly 420 is manufactured. Then, the coreassembly 420 is placed into a wax die. Wax 430 is then injected aroundthe core assembly 420. The external pattern of airfoil 100 is producedby the injected wax 430. The mold assembly comprising the core assembly420 and the wax 430 is then placed on a tree assembly. The tree assemblyis then dipped into ceramic to make external shell 410 outside of thewax 430 and resulting in casting assembly 400. Next, the castingassembly 400 is heated and the wax 430 is melted and removed from thecasting assembly 400 resulting in casting assembly 401, as shown in FIG.5B.

In various embodiments, with reference to FIG. 5B, after the wax 430 hasbeen removed from the casting assembly, distal end 324 of pin 320 mayabut external shell 410. During casting, a metal alloy is dispersedthrough the space between the inner surface 414 of external shell 410and core assembly 420. The bumper assembly 300 may allow repeatablepositioning on an airfoil 100 (from FIG. 2 ), since the pin 320 maymerge into the finished casting of the airfoil 100 and/or may eliminatea hole through the airfoil 100 and/or between ribs of the airfoil 100.

With reference to FIG. 6 , a cast core 500 including a bumper assembly505, in accordance with various embodiments, is illustrated. Cast core500 comprises an outer surface 502 and a bumper assembly 505 extendingoutward from outer surface 502. In various embodiments, bumper assembly505 is integral to the cast core 500. Bumper assembly 505 comprises abumper 510 and a sphere 520. The sphere 520 may be disposed partiallywithin the bumper 310. Although depicted as a sphere 520 in FIG. 6 , anda pin 320 in FIGS. 4 and 5 , any metallic apparatus partially disposedin a bumper of a cast core and protruding away from the bumper of thecast core is within the scope of this disclosure.

In various embodiments, the bumper 510 comprises a fillet 512 coupling aproximal edge 513 of bumper 510 to the outer surface 502 of the castcore 500. The fillet 512 may reduce stress concentrations during thecasting process. In various embodiments, bumper 510 is a truncated cone514 extending from proximal edge 513 to distal edge 515. The bumper 510further comprises a receptacle 516 extending from distal edge 515 intothe bumper 510. Receptacle 516 may be a recess and may comprise asemi-spherical shape. In various embodiments, the receptacle 516 mayhave a depth less than a height measured perpendicular to outer surface502 from outer surface 502 to distal edge 515. In various embodiments,the bumper 510 is integral to the cast core 500. The bumper may be madefrom ceramic composite, or any other material known in the art.Similarly, the cast core may be made from ceramic composite, or anyother material known in the art.

In various embodiments, the bumper 510 may comprise the receptacle 516.The sphere 520 may be inserted into the receptacle 516 and coupled viaan adhesive or a mechanical lock. By integrating the sphere 520 into abumper assembly 505 of a cast core 500, the manual process of insertinga pin into a wax pattern and blending the pin off post casting may beeliminated.

With reference to FIG. 7A, a cross-sectional view of a casting assembly600 prior to casting, in accordance with various embodiments, isillustrated. In various embodiments, the casting assembly 600 comprisesan external shell 610, a core assembly 620, and a wax disposed betweenthe core assembly 620 and the external shell 610. In variousembodiments, external shell 610 comprises an outer surface 612 and aninner surface 614 disposed opposite the outer surface 612. In variousembodiments, casting assembly 600 comprises a casting core 500 and abumper assembly 505. In various embodiments, a distal end 524 of sphere520 between 0.000 inches and 0.006 inches (0.000 cm and 0.015 cm) frominner surface 614 of external shell 610, or between 0.002 inches and0.006 inches (0.005 cm and 0.015 cm), or between 0.003 inches and 0.005inches (0.008 cm and 0.013 cm). In various embodiments, distal end 524of sphere 520 contacts inner surface 614. In various embodiments,25%-75% of a surface area of sphere 520 is disposed within receptacle516 of bumper 510, or between 35% and 65% of the surface area, orbetween 40% and 60% of the surface area.

In various embodiments, the external shell 610 is made of ceramiccomposite, or any other material known in the art. In variousembodiments, the core assembly 620 is manufactured. Then, the coreassembly 620 is placed into a wax die. Wax 630 is then injected aroundthe core assembly 620. The external pattern of airfoil 100 (from FIG. 2) is produced by the injected wax 630. The mold assembly comprising thecore assembly 620 and the wax 630 is then placed on a tree assembly. Thetree assembly is then dipped into ceramic to make external shell 610outside of the wax 630 and resulting in casting assembly 600. Next, thecasting assembly 600 is heated and the wax 630 is melted and removedfrom the casting assembly 600 resulting in casting assembly 601, asshown in FIG. 7B.

In various embodiments, with reference to FIG. 5B, after the wax 630 hasbeen removed from the casting assembly, distal end 524 of sphere 520 mayabut external shell 610. During casting, a metal alloy is dispersedthrough the space between the inner surface 614 of external shell 610and core assembly 620. The bumper assembly 505 may allow repeatablepositioning on an airfoil 100 (from FIG. 2 ), since the sphere 520 maymerge into a finished casting of the airfoil 100 and/or may eliminate ahole through the airfoil 100 and/or between ribs of the airfoil 100.

With reference now to FIG. 8 , a method of manufacturing a casting coreassembly, in accordance with various embodiments, is illustrated. Themethod comprises forming a casting core having an outer surface (step802). The casting core may be made of a ceramic matrix, or any othermaterial known in the art. Next, a pin may be inserted into the outersurface of the casting core (step 804). A ceramic composite may beinjected around the pin and form a bumper assembly on the outer surfaceof the casting core (step 806). In various embodiments, the casting coreassembly may be as illustrated in FIGS. 4 and 5 . Next, the casting coreassembly may be heated forming a solid casting core assembly thatcouples the pin to the casting core assembly (step 808). Then, thecasting core assembly may be placed in a wax die and wax may be injectedaround the casting core assembly (step 810). In various embodiments, thewax may enclose the bumper assembly within it.

In various embodiments, the method may further comprise forming anexternal shell around the injected wax (step 812). Forming the externalshell may be done by placing the casting core assembly and wax on a moldwith a tree assembly and dipping the casting core assembly and wax intoa ceramic matrix slurry. The ceramic matrix slurry may be heated toharden the external shell resulting in a casting assembly as illustratedin FIG. 5A. In various embodiments, the method further comprises heatingthe casting assembly (step 814). Next, the wax may be removed as itbecomes liquified during step 814 (step 816). In various embodiments,the casting assembly from FIG. 5B may be produced by step 816.

With reference now to FIG. 9 , a method of manufacturing a casting coreassembly, in accordance with various embodiments, is illustrated. Themethod comprises forming a casting core having a bumper disposed on anouter surface (step 902). In various embodiments, the bumper may be inaccordance with FIGS. 4-7B. The bumper may comprise a truncated cone anda receptacle disposed at an outer surface of the truncated cone. Thecasting core and bumper may be made of a ceramic matrix, or any othermaterial known in the art. The method further comprises inserting ametal apparatus into the receptacle of the bumper (step 904). The metalapparatus may be a pin, a sphere, or any other metal apparatus known inthe art. In various embodiments, the metal apparatus is made ofplatinum. The method may further comprise coupling the metal apparatusto the bumper (step 906). The metal apparatus may be coupled to thebumper by an adhesive and/or a mechanical lock. After the metalapparatus is coupled to the bumper a casting core assembly, asillustrated in FIGS. 4-7B may be formed. The method further comprisesinjecting wax around the casting core and bumper assembly (step 908).This may be done by placing the casting core assembly in a wax dieinjecting the wax around the casting core assembly. In variousembodiments, the wax may enclose the bumper assembly within it.

In various embodiments, the method may further comprise forming anexternal shell around the injected wax (step 912). Forming the externalshell may be done by placing the casting core assembly and wax on a moldwith a tree assembly and dipping the casting core assembly and wax intoa ceramic matrix slurry. The ceramic matrix slurry may be heated toharden the external shell resulting in a casting assembly as illustratedin FIG. 5A of FIG. 7A. In various embodiments, the method furthercomprises heating the casting assembly (step 914). Next, the wax may beremoved as it becomes liquified during step 914 (step 916). In variousembodiments, the casting assembly from FIG. 5B may be produced by step916.

Benefits and other advantages have been described herein with regard tospecific embodiments. Furthermore, the connecting lines shown in thevarious figures contained herein are intended to represent exemplaryfunctional relationships and/or physical couplings between the variouselements. It should be noted that many alternative or additionalfunctional relationships or physical connections may be present in apractical system. However, the benefits, advantages, and any elementsthat may cause any benefit or advantage to occur or become morepronounced are not to be construed as critical, required, or essentialfeatures or elements of the disclosure. The scope of the disclosure isaccordingly to be limited by nothing other than the appended claims, inwhich reference to an element in the singular is not intended to mean“one and only one” unless explicitly so stated, but rather “one ormore.” Moreover, where a phrase similar to “at least one of A, B, or C”is used in the claims, it is intended that the phrase be interpreted tomean that A alone may be present in an embodiment, B alone may bepresent in an embodiment, C alone may be present in an embodiment, orthat any combination of the elements A, B and C may be present in asingle embodiment; for example, A and B, A and C, B and C, or A and Band C.

Systems, methods and apparatus are provided herein. In the detaileddescription herein, references to “various embodiments”, “oneembodiment”, “an embodiment”, “an example embodiment”, etc., indicatethat the embodiment described may include a particular feature,structure, or characteristic, but every embodiment may not necessarilyinclude the particular feature, structure, or characteristic. Moreover,such phrases are not necessarily referring to the same embodiment.Further, when a particular feature, structure, or characteristic isdescribed in connection with an embodiment, it is submitted that it iswithin the knowledge of one skilled in the art to affect such feature,structure, or characteristic in connection with other embodimentswhether or not explicitly described. After reading the description, itwill be apparent to one skilled in the relevant art(s) how to implementthe disclosure in alternative embodiments.

Furthermore, no element, component, or method step in the presentdisclosure is intended to be dedicated to the public regardless ofwhether the element, component, or method step is explicitly recited inthe claims. No claim element is intended to invoke 35 U.S.C. 112(f)unless the element is expressly recited using the phrase “means for.” Asused herein, the terms “comprises”, “comprising”, or any other variationthereof, are intended to cover a non-exclusive inclusion, such that aprocess, method, article, or apparatus that comprises a list of elementsdoes not include only those elements but may include other elements notexpressly listed or inherent to such process, method, article, orapparatus.

What is claimed is:
 1. A method of manufacturing a casting assembly, themethod comprising: forming a casting core having an outer surface;inserting a pin into the outer surface of the casting core to a depthbelow the outer surface; subsequently injecting a ceramic composite onlyaround the pin above the outer surface to form a bumper that extendsoutward from the outer surface and to couple the pin to the castingcore, the pin partially extending outward from the bumper; heating thecasting core, the ceramic composite, and the pin to form a casting coreassembly including a bumper assembly; injecting a wax around the castingcore and the bumper assembly; forming an external shell around the wax;and heating the casting assembly and removing the wax from the castingassembly.
 2. The method of claim 1, wherein the wax encloses the bumperassembly.
 3. The method of claim 1, wherein the forming the externalshell further comprises dipping the wax into a ceramic matrix slurry. 4.The method of claim 1, wherein the pin is spaced apart from the externalshell in response to forming the external shell around the wax.
 5. Themethod of claim 4, wherein an inner surface of the external shell abutsthe pin in response to heating the casting assembly and removing the waxfrom the casting assembly.